If you teach math or help your kids with homework, you should definitely own (and use) math dice.
You may be of the mind that math is "serious" and dice is "fun and games". My answer to that is, they are both true. Math is serious...so serious, in fact, that we should be using every tool at our disposal to help kids learn it. And as it turns out, play is one of the best teaching tools there is.
When kids are learning math, dice can help with three big areas: learning math concepts, learning math skills, and practicing what they have learned.
Math concepts are the big ideas behind the math problems that kids do. For example, first graders are mastering addition. Memorizing math facts (4+3, 2+2, and so on) is a skill.
But for a skill to make sense, they need to understand some concepts: that putting two groups of things together gets you a bigger whole, that 4+3 and 3+4 will get the same result, and so on. Math concepts give context to skills.
When kids are learning new concepts, dice games give them a chance to use counters, money, or other math tools in a real-life situation.
Skills often involve remembering steps or memorizing answers to common problems.
Development of math skills often takes time and a lot of repetition. Dice games are perfect for giving kids the practice they need. Because kids like games, they don't mind playing a math game over and over, and the more they play, the more they learn.
Dot dice have six sides and go from numbers 1 to 6. These are a must-have, in my opinion. I recommend having at least 6, as dice get lost and some games use as many as 6 dice.
Numeral dice have numbers written on them instead of dots. These are especially important when doing place value, since you can physically form a large number and see what it looks like. Numeral dice are usually not added together; the numbers are put together to make one many-digit number.Giant dice come with either dots or numerals in a variety of sizes. I get the biggest I can find. Kids love them, and you can use them with larger groups.
You might also be interested in the article Playing Cards for Math.